1. Field of the Invention
The present invention is directed to conveyor systems, and more particularly to merging conveyor systems.
2. Description of Related Art
Conveyor systems are used to transport goods, packages, cartons and other objects in all types of environments and experience heavy use in the manufacturing and shipping industries. Complex conveyor systems typically require the merging of several conveyor lines into one main line. As such, apparatuses for the effective merging of cartons from multiple conveyor lines are important to the conveyor industry. Of additional importance is the ability to create and control gaps between cartons in order to facilitate sorting.
To effectively merge a package from a merging conveyor line onto the main conveyor line, the merging conveyor typically abuts the main line in such a manner as to allow the transfer of cartons from the merging line to the main line. Conventional merging conveyor systems include “spur” merges and “sawtooth” merges. A typical spur merge includes a roller merge line that abuts a roller main line at an angle acute to the direction of the main line. The axis of the rollers of both the main line and the spur line are perpendicular to the direction of their travel, respectively.
A typical sawtooth merge includes a belt merge line that abuts a roller main line at an angle acute to the direction of travel of the main line. However, unlike a spur merge, the main line has a triangular sawtooth area that projects out from the main line so as to accommodate the end of the belt merge line. The sawtooth area is created by extending the main line rollers that are adjacent the sawtooth into the sawtooth area.
In order to create and control gaps between cartons on the main line of a conveying system, typical conveyor systems employ a separation station. This may include a series of conveyor sections with progressively increasing speeds. Cartons that reach the faster conveyor sections first are pulled ahead of the cartons behind them due to the differences in velocity. The delays on the slower conveyor sections between cartons create bigger gaps between the cartons on the faster conveyor sections.
Controlling gaps between cartons is also advantageous at the merging area. In order to control such gaps in typical merge systems, pop-up stops, brake rollers, brake belts or other similar traffic control devices are used. Despite the use of these devices, however, there remains a problem in controlling the positioning of cartons. Oftentimes, a conveyor must accommodate assorted cartons, including cartons that are not uniform in size, shape, weight or condition. When traveling on a typical roller line, non-uniform cartons do not travel at the same speed due to slippage between the contacting surface of the carton and the surface of the rollers. This necessitates the need for a separation station downstream from the merging area.
Thus, there remains a need for a merging conveyor system that can accurately control the position of cartons from the merging line to the main line. Such positional control can enable the conveyor system to run more efficiently and can eliminate the need for a separation station downstream from the merging area.